Dynamic Light Scattering ( DLS ) enables the characterization of sizes and electrokinetic properties of colloids, polymers, macromolecules. DNA is a charged semiflexible polyelectrolyte, which is condensed or compacted by counterions, proteins, and other condensing agents in processes such as chromosome compaction and gene therapeutic applications. DNA condensation is closely related to charge screening, since packaging requires effective neutralization of its surface negative charges. In this chapter, we describe in detail the protocol for DLS of DNA-ligand complexes. As an example, we describe data for condensation of DNA by chitosan and the measurement of size, zeta potential, and electrophoretic mobility of the DNA-ligand complex by DLS.
Keywords: Chitosan; DNA condensation; Dynamic light scattering; Electrophoretic mobility; Zeta potential.